Siobhan is worried about his grade in geosciences. The instructor has already explained that the exam will be graded on a curve and although Siobhan has been studying all semester, there are so many bright students in the class, his grades are always in the middle of the curve. He know he needs an advantage. Two weeks before the exam, the professor announces that there are three texts that she will put on reserve in the library and explains that students who are interested in earning extra credit should read those three texts and then answer the extra credit questions on the exam. She explains that no one is required to do the extra credit. but those do so will have the points they earn added into their point count for the final. Siobhan goes to the library to check out the texts, which have been placed on two hour reserve. It dawns on him that he can get the edge that he needs on the grading curve if he is the only one who answers the extra credit. He decides not to return the texts to the library.
It really depends on when he checked the books out and how long he kept them, as well as the directions that were given to him. Definitely unethical. But probably not a violation of AI, since the other students had other means of getting the books.